The Cohabitation Agreement That Held Up Nine Years Later

The situation

Kofi and Xia met in their late twenties and moved in together in Ancaster after about a year of dating. Kofi worked as a software developer and had spent the prior several years buying a small investment portfolio and building equity in a condominium he owned outright before the relationship began. Xia was completing her final year of pharmacy training at the time and had modest savings by comparison.

Before they moved in together, Kofi's friend Yan, who had been through a messy split of his own after moving in with a partner without any agreement in place, urged Kofi to think about a cohabitation agreement, a contract that two people who plan to live together, but are not yet married, can sign to set out how property and support would be handled if the relationship ended. In Ontario, the Family Law Act allows unmarried couples to enter into these agreements, and if a cohabiting couple later marries without changing the terms, the same agreement generally continues to apply as a marriage contract. Kofi wanted his condominium and existing investments protected as his own, separate from anything the couple built together going forward. Xia agreed the idea was fair, and the couple retained separate lawyers to negotiate the terms rather than having one lawyer draft it for both of them.

The agreement they signed, about four months before they moved in together, excluded Kofi's condominium and his existing investment portfolio from any future division, while treating income earned during the relationship, a future joint home, and any property bought together as shared. Each of them attached a sworn financial statement listing their assets, debts, and income as of the date of signing.

The challenge

Nine years later, after the couple had married, sold Kofi's original condominium, and bought a larger home together in Ancaster, the relationship ended. By then Xia had built a career as a pharmacist and their combined household income sat comfortably in the upper range for the area. Kofi came to Treadstone Law wanting to separate on the terms the couple had agreed to years earlier: the appreciation on his original investment portfolio, now grown to roughly $180,000, would stay his, while the home the couple had bought together, worth roughly $600,000 with about $250,000 in equity, would be divided according to the contract's formula for jointly acquired property.

Xia's lawyer disagreed. Their position was that the cohabitation agreement should be set aside entirely. The arguments raised were ones that come up often when older domestic contracts are challenged years after signing: that Xia had not fully understood what she was giving up as a student with little in the way of assets at the time, that the financial disclosure attached to the agreement did not reflect Kofi's true net worth, and that nine years of marriage and a shared home had made the original terms unfair to enforce now. If a court agrees that a domestic contract was signed without proper financial disclosure, without a genuine understanding of the other party's rights, or under circumstances that were not truly voluntary, the Family Law Act allows the contract to be set aside in whole or in part.

The stakes were real. If the agreement fell, the entire nine years of accumulated wealth, including the growth on Kofi's original portfolio, could be treated as part of the pool subject to equalization, the process where each spouse's net family property is compared and the spouse with more pays the other roughly half the difference.

What we did

1. Pulled the original file and confirmed independent legal advice. The agreement itself recorded that Xia had retained her own lawyer, separate from Kofi's, and each lawyer had signed a certificate confirming they had explained the agreement to their own client. We obtained copies of those certificates, which is often the single strongest piece of evidence against a claim that a party did not understand what they were signing.
2. Reviewed the financial disclosure attached to the agreement. Both financial statements from the time of signing were still on file, sworn and dated. Kofi's statement listed the condominium's estimated value and the investment portfolio's balance as of that date. Because the agreement disclosed the existence and approximate value of the assets being excluded, rather than staying silent about them, it met the disclosure standard the Family Law Act requires even though the exact investment values had since grown substantially.
3. Built a timeline showing the agreement was not signed under pressure. A pattern courts look for in these challenges is whether an agreement was presented on the eve of a wedding or move-in date, leaving little real opportunity to negotiate or walk away. Here, the agreement was signed roughly four months before the couple moved in together, with several rounds of negotiation between the two lawyers in between. We documented that timeline with the original correspondence between the two original lawyers.
4. Traced the condominium sale proceeds through to the current portfolio. Because the condominium had since been sold and the money reinvested, we needed to show that the funds excluded under the agreement could still be identified and traced through to what Kofi now held, rather than having become mixed beyond separation with jointly earned income.
5. Responded to the fairness argument directly. We did not dispute that nine years is a long marriage, or that Xia's own career and income had grown substantially. Instead, we pointed to the contract's own terms, which already treated the home and post-cohabitation income as shared. The agreement was not asking Xia to leave with nothing; it was asking that the one asset excluded from the start stay excluded.
6. Negotiated rather than proceeding straight to a court motion. With the disclosure and independent advice records assembled, we shared them with Xia's lawyer before either side filed anything formally, along with a proposed separation agreement that mirrored the original contract's terms for the home and left the excluded portfolio out of the calculation.

The outcome

Faced with a well-documented file, including signed disclosure statements, independent legal advice certificates, and a negotiation timeline that undercut any claim of pressure, Xia's lawyer did not pursue a formal application to set the agreement aside. The couple settled on terms consistent with the original cohabitation agreement: the home in Ancaster was sold, with the roughly $250,000 in equity divided according to the formula the couple had agreed to years earlier, and Kofi's investment portfolio, now worth roughly $180,000, stayed his alone.

The one point of real negotiation was spousal support. The original agreement had not addressed support at all, which meant it remained an open question governed by ordinary family law principles rather than the contract. Given the length of the marriage and the income gap that had existed for parts of it, the couple agreed to a modest, time-limited support arrangement, separate from and unaffected by how the property was divided.

The agreement held up not because it favoured Kofi, but because it had been built to last a challenge from the start: independent lawyers on both sides, honest disclosure of what was being excluded, and enough time between signing and moving in together that no one could credibly say it was signed under pressure. Those same three features are what a court, or an opposing lawyer deciding whether a fight is worth having, looks for first.

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